Percussive-tool machine.



P. BADE. PEROUSSIVE TOOL MACHINE.

APPLIOATION FILED MAY 19, 1911. 1,041,569.

2 1 9 1 F0 1 m 0 d m m h 6 M iiiafl r /4 0/ 4 my 6U C MM 0 6% v "WM/3% 1(Ml W f g Wm tint FRANZ BADE, 0F PEINE, GERMANY.

PERCUSSIVE-TOOL MACHINE.

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Specification of Letters Patent.

Patented oat; as, was.

To all whom it may concern:

Be it known that I, FRANZ BABE, a sub-- ject of the German Emperor,residing at Peine, in Germany, have invented certain new and usefulImprovements in Percussive- Tool Machines, of which the following is aspecification.

This invention relates to portable rockdrills and other machines forworking stone and the like by means of percussive tools operated by anelectric motor forming part of the machine.

In machines of this class lightness and simplicity are of greatimportance, more particularly if the apparatus is to work while merelyheld by hand, without fixed support, and the object of the presentinvention is to provide certain improvements in'this respect.

The invention is illustrated in the accompanying drawing, in whichFigure 1 is a longitudinal section of the machine,-and Fig. 2 a diagramillustrating a detail thereof.

The motor comprises the stator a and axially movable rotor b, the cover0 of the motor case being formed with a handle. A tubular piece (2 fixedto the front end of the stator forms a guide for the axially movabletool 2'. The rotor is thrust by a spring e against a ball f, which worksbetween two grooved race-plates g 9 the plate 9 being fixed to the rotorand the plate g being fixed to an elastic ring h in the motor casing.The groove inthe plate 9 is level, but the plate g is a cam-plate,having a ridge or elevation, gently rising onone side and more steeplyinclined on the other, as shown in Fig. 2.

When the motor is working the ring 1 rotated by the rotor, drives theball f around its race, and the ball, traveling up'the gentle incline,forces the rotor rearward and compresses the spring e. When the ball haspassed the crest of the incline, the spring thrusts the rotor forward,so that the rotor spindle acts by ercussion on the tool 2'. Thecushioning ring h absorbs shock, and equalizes the impact.

The tool used may be either a percussive boring tool or a chisel or thelike.

What I claim as my invention and desire to secure by Letters Patent ofthe United States is 4 1. In a percussive tool machine the combinationof acasing having a tool guide and bearings for a rotor, a statormounted in said casing, an axially reciprocatable rotor having a shaftmounted in said bearings, a

percussive tool positioned in the path of the axial movement of saidshaft, and means w1th1n the casing for reciprocating sald rotor duringits rotation.

. 2. In a percussive tool machine the combination of a casing having atool guide and bearings for a rotor, a stator mounted in said casing, anaxially reciprocatable rotor having a shaft mounted in said bearings, a

percussive tool positioned in the path of the axial movement of saidshaft, a cam device within the casing whereby axial movement in onedirection is imparted to said rotor during its rotation, and a springbearing on said rotor in the opposite direction.

3. In a percussive tool machine the combination of a casing having atool guide and bearings for a rotor, a stator mounted in said casing, anaxially reciprocatable rotor having a shaft mounted in said bearings, apercussive tool positioned in the path of the axial movement of saidshaft, a cam-plate within the casing having a ball race, a ball in saidrace, and a spring axially thrusting the rotor against said ball, sothat the rotor is reciprocated during its rotation.

In witness whereof I have signed this specification in the presence oftwo witnesses.

. FRANZ Witnesses:

CARL SGHURIGER, CARL Demos.

